US-based buyout firm Kohlberg Kravis Roberts has teamed with European private equity group Rhone Capital to increase their offer by 10.6 per cent to $5.20 a share.

The new offer adds 50 cents to the prior offer from KKR, which the Treasury Wine board rejected back in April and a 41 per cent premium on the then share price, which was $3.69.

The current offer is 5.1 per cent above Treasury's Friday closing price of $4.95 per share.

Unlike KKR's initial approach, the new offer has pricked the interest of Treasury's board which issued a statement urging shareholders not to dismiss it.

"The board of TWE, together with its advisers, has concluded, based on the revised proposal, that it is in the interests of its shareholders to engage further with KKR and Rhone," the announcement said.

The board warns investors though that it is not a done deal and remains subject to several conditions including the completion of due diligence to the satisfaction of the buyers.